#include <iostream>

struct A {
  double x;
};

A* a = new A{0};

decltype(a->x) y= a->x;

template <typename T, typename U>
auto add(T t, U u) -> decltype(t+u){
  return t+u;
}

int main(){

  y = 2.0;

  std::cout << "y= " << y << ", x=" << a->x << std::endl;

  auto f = [] (int a, int b) -> int {return a*b;};

  decltype(f) g = f;
  

  std::cout << "f(3,5)=" << f(3,5) << ", add: " << add(3,5) << std::endl;


  
  
}